Automatic telephone-calling transmitter



Jan. 19 1926.

Fig. 1-

s. w. BALCH AUTOMATIC TELEPHONE CALLING TRANSMITTER Filed June 5; 1924 3 Sheets-Sheei l W W M -W 1,570,030 s. w. BAI ,CH

AUTOMATIC TELEPHONE CALLING TRANSMITTER Jan. 19 1926.

1924 3 Sheets-Sheet 2 Filed June 5,

Flg. 4.-

Inventor,

Jan. 19 1926. 1,570,030

S. W. BALCH AUTOMATIC TELEPHONE CALLING TRANSMITTER Filed June 5, 1924 s Sheets-Sheet :5

Inventor WZ IQLKA Patented Jan. 19, 1 926.

UNITED STATES SAMUEL W. BALGH, 0F MONTCLAIB, NEW JERSEY.

AUTOMATIC TELEPHONE-CALLING TRANSMITTER.

Application filed June 5. 1924. Serial No. 717,946. ,a

To all whom it may concern:

Be it known that I, SAMUEL W. BALCH, a citizen of the United States of America, residing at Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Automatic Telephone-Calling Transmitters, of which the following is a full description.

In the case of most telephone users a large portion of the calls are to a limited number of stations, and of these there are usually a few stations which are repeatedly being called, and any means for reducing.

the efi'ort in calling such stations will result in material labor saving for telephone subscribers and their private-branch exchange operators. Where such subscribers are connected to. an automatic exchange they have to go through the operation of turning a dial successively to theletters and digits which spell out the call designation of the desired station. In a metropolitan section like New York, in orderto provide sufiicient designations for the million and more stations, it is necessary to use seven letters or digits in each call designation, and in making a call these must be successively selected on a dial, the dial turned to a stop, released, permitted to fully return to the initial position at a governed speed, and the operation repeated untilthe seven letters and digits have been dialed.

The object of this invention is to provide an automatic calling transmitter by which such laborious operation is not required of the telephone subscriber or of his privatebranch exchange operator in effecting connection to frequently called stations, and in which, by reason of the substitution of automatic operation for manual operation, possibility of error is avoided.

A further object is to provide a transmitter which takes a minimum of time in its operation, and in which the operators attention is released as soon as the automatic o eration of making a call has been initiated: so that, in the case of a private branch exchange where several trunks are to be handled, the operator can, while the apparatus is effecting a connection over one trunk, be attending to an incoming call over another trunk or to other duties.

A further object is to provide an automatic transmitter which utilizes records made on inexpensive cards of the size most commonly used in cataloguing so as to be readily obtainable, and in which the record on each card is of a simple and easily understood character and which can be made without the use of specially designed implements.

A further object is to provide a transmitter by which connections may be made either automatically after the insertion of such a card or manually, as to an infrequently called station for which no card has been provided, and in which the impulses are transmitted in either case through the same electrical contacts, thereby avoiding a duplication of such contacts in series with the added chance of a poor connection.

A further object is to 'rovide an automatic transmitter with which a dial of substantially standard construction is incorporated, and which is so associated that it will be free for manual operation, exce t when the automatic apparatus is actual y functionin and without'having to operate any specia switch or connection.

The effecting of a telephone connection through an automatic exchange involves the transmission of a series of groups of electrical impulses, the impulses in each group numbering from one to ten and following each other at close intervals between certain narrow limits and the successive groups being distinguished by larger separating intervals. For manual operation a dial is used, and for association with this automatic transmitter it may have such features as are set forth in United States Patents N 0. 1,337,314, No. 1,390,679, and No. 1,454,496, to mention a few which are representative.

In the accompanying three sheets of drawin s which form a part of this descriptionigure 1 is a plan View of an automatic calling transmitter embod ing this invention, including the dial an arm which carries the stylus with a card fully inserted, other elements being omitted from this figure.

Fig. 2 shows a printed and perforated 'card' such as is used in the automatic operation.

Fig. 3 is a plan view showing the card inserted and the arm carrying the stylus at a perforation.

Fig. 4 is a front elevation showing the comb for guiding the stylus, the driver, feed-cam, spring-barrel, governor, and inter connectin gearing.

Fig. 5 1s a side elevation, partly in section, showing the several parts, excepting the governor.

Fig. (3 is a plan showing the feed levers, feed cam, governor and interconnecting gearing.

For the automatic operation of the transmitter a rectangular card 11 is provided for each station which it is anticipated may be frequently called. At the upper edge of the card is space for entering the name of the party at the station to be called with the aid of the card. The card is shown as arranged for use where connection is made by seven groups of impulses. As the first three groups may differ in eight ways there are eight positions provided on each of the first three lines printed on the card showing the distribution of the letter designations used to distinguish these groups. The last four groups may each difi'er in ten ways, and ten positions are provided on each of the last four lines printed on the card for which there are numerical designations from one to nine and then naught.

The call is recorded on the card by seven punch holes, one in each ,line, and the holes are positioned in the successive lines according to the letters and digits which make up the call number. There being so few holes to a card, they may be conveniently made with a hand punch having a reach equal to at least half the width of the card. The card is inserted in the automatic apparatus from the rear and is supported on a table 12.

A dial 13, which may be used manually, surmounts the transmitter. It carries the usual finger-plate 14, impulse wheel 15, dialshaft 16, striker arm 17, and contact springs 19, 19. A dial-spring 21 returns the finger plate, and a dial-governor 22 limits the speed of return when the impulses are transmitted.

For automatic operation from cards a pinion 23 is carried on the dial-shaft. Through an intermediate pinion 24 connection is made with a segment 25 which is loose on a main shaft 26. Hinged to the segment is a traversing arm 27 hearing a stylus 29 which moves with the segment and traverses the lines-on the card. The hinge connection permits the stylus to move at right angles to its traversing movement and enter a perforationwhenever it comes over one. The stylus is kept from touching the card in traversing except at the centers of the positions on each line by reason of a stop pin 31 which is carried by the traversing arm and rides along the top of a comb 32 but does not drop into the slots between the teeth sufficiently to arrest the traversing arm unless the stylus is over a perforation.

A three-arm driver 33 carried loosely on the main shaft engages a tongue 34 on the traversing arm to actuate it and carry with it the dial until the stylus is brought over a perforation when the tongue drops below a the driver arm and permits the arm to pass.

Immediately on passing, the following arm of the driver comes against an incline 35 on the underside of the traversing arm and lifts the stylus clear of the perforation and the stop pin out of the slot in the comb. The comb )revents the stylus from striking the edge of the perforation in the card and thereby saves the card from much wear and injury.-

Vhen the following driver-arm reaches the position for engagement with the tongue for a succeeding operation of the traversing arm, the driver is checked by a stop-lever 36 and held until the traversing arm has completed its excursion and has returned to its initial position when the stop lever is cammed out of the way. Return of the traversing arm is effected by the dialspring and under control of the dialovernor. As dials are ordinarily organized it is during this return movement that the transmission of a group of impulses takes place and the number in the group depends on the amplitude of the movement. As there are three arms on the driver, three excursions are effected by each revolution, and as there are seven groups of impulses to be transmitted, each group being controlled from one of the seven lines of the card, means are provided for feeding the card by a cam 37 which makes one revolution while the driver makes two and onethird revolutions, a ratio of three to seven. They are therefore connected by a gear train consisting of an eighteen-tooth gear 18 attached to the driver meshing with a thirty-tooth gear 30 which is connected with a twenty-tooth gear 20 in mesh with a twenty-eight-tooth gear 28 attached to the cam. The cam has seven lands. The card is fed by levers 38 and 39, which are connected by a link 40,- and a pin 41 on this link is engagedby the cam. The feed is effected when the pin rides on the cam from one land to the next, and the cam is set so that this takes place while the traversing arm is about at its initial position or between the initial position and the first osition on the line at which there may e a perforation so that the feeding operation will not move a perforation under the stylus.

In preference to applying manual power directly either to the driver or to the cam and through the interconnecting train to the other, the power is applied through a coiled spring 42 in a spring-barrel 43 attached to the cam. The inner end of the spring is attached to the main shaft which is turned by a crank 44. ()n the main shaft is a single-tooth ratchet 45 held by a pawl 46 so that one complete turn is made in I stylus, means for traversing the stylus relawinding. More than a single turn in Winding or unwinding is prevented by a lip 47 on the ratchet coming into engagement with a pin 48 on the barrel. The spring can be wound up with one quick turn, and the operator can give attention to other matters while the'transmitter is functioning.

In order to prevent too rapid action and give the stylus time to drop when over a perforation a suitable retarding device is employed which consists of afconnection through a gear train with a fifty-four tooth gear 54 meshing with a nine-tooth gear 9 which is connected with a seventy-tooth gear in mesh with a seven-tooth pinion 7 which actuates a variable movement consisting of a crank 49 which engages a radially disposed slot in the side of an eccentrically positioned fly-wheel 50 and drives a governor 51. The successive positions on each line of the card at which there may be a perforation are six degrees apart, or onesixtieth part of a revolution in the move- .ment of the traversing arm. The above train is therefore toothed for a ratio of one to sixty so that the movement will be checked at each position and the stylus Wlll have time to drop 'if over a perforation. This connection is not made to the dialgovernor because the dial-governor does not make precisel one revolution to each position as dials fiave been standardized.

To operate the transmitter, a card punched for the desired call is selected, placed on the table and pushed in as far as it will go, pushing back the feed levers. The circuits being right for dialing, the crank is given one turn, and then the trans mitter automaticall sends the required groups of impulses or effecting the connections.

I claim 1.A calling transmitter controlled by a perforated card comprising means for transmitting impulses in rapid succession independently of perforations in the card, means for interrupting and separating the transmission of the impulses into groups of various numbers of impulses, and means traversing the perforated card for controlling the sizes of the several groups from the locations of the perforations.

2. A calling transmitter controlled by a perforated card comprising means for transmitting impulses in rapid succession independently of perforations in the card, means for interrupting and separating the transmission of the impulses into a series of groups of various numbers of impulses,

and means traversing along a corresponding series of lines on the perforated card having a perforation located on each line for controlling by its position the size of the corresponding group of impulses.

3. A calling transmitter comprising a along lines on a perforated card having a perforation located on each line,- means for arresting the traversing of the stylus when it enters a perforation, means for withdrawing the stylus from each perforation and returning it to the commencement of a succeeding line, and means operating on each operation of the stylus for transmitting a group of impulses.

5. A calling transmitter comprising a stylus, means for traversing the stylus relative to a perforated sheet, means for arresting'the traversing of the stylus when it enters a perforation, means for withdrawing the stylus from each perforation and permitting the continuation of its traversing to another perforation, and means operating on each operation of the stylus for effecting a group of impulse transmissions the number of which in eachgroup depends on the distance of the traverse in each operation.

6. A callin transmitter comprising a stylus, means for traversing the stylus along lines on.a perforated card having a perforation located on each line, means for arresting the traversing of the stylus when it enters a perforation, means for withdrawing the stylus from each perforation and returning it to its initial position, means for effecting a line feed between each excursion of the stylus, and means operating on each excursion of the stylus for effecting a group of impulse transmissions the number of which depends on the amplitude of the excursion.

7. A calling. transmitter comprising a traversng arm bearing a stylus movable at right angles to the traversing movement of the arm, a driver for traversing the stylus across a erforated card by contact with a part of t e arm which is moved out of the path of the driver when the stylus enters a perforation, means operating with the movement of the driver past the traversing arm for withdrawing the stylus from the perforation, means for restoring the travers ing arm to its initial position after Withdrawal of the stylus, means for preventing reengagement of the driver with the travering the card between each excursion of the traversing arm, and means operating on each excursion of the traversing arm for efiecting a group of impulse transmissions the num ber of which in each group depends on the amplitude of the excursion.

8. A callin transmitter comprising a dial capable manual operation, and means traversing a perforated sheet for automatically controlling the amplitude of successive movements of the dial from the locations of the perforations.

9. A calling transmitter comprising. a dial capable of manual operation for transmitting a series of groups of various numbers of impulses by a corresponding series of movements, and means traversing along a corresponding series of lines on a perforated card for controlling the size of each of the several groups from the location of the perforation on each of the corresponding lines.

10. A callin transmitter comprising a dial capable of manual operation, a stylus, and means for traversing the stylus relative to a perforated sheet for automatically controlling the amplitude of successive movements of the dial from the locations of the perforations.

11. A calling transmitter comprising a dial capable of manual operation for transmittin a series of groups of various numbers 0% impuIses by acorresponding series of movements, a stylus, and means for traversing the stylus along a corresponding series of lines on a erforated card for automatically controlling the amplitude of cone sponcling movements of the dial from the cations of the perforations.

12. A calling transmitter comprising a stylus, means for traversing the stylus relative to positions on a erforated sheet at which there may be per orations, means for retarding the traversing movement at each position, means for arresting the traversing of the stylus, means for arresting the naversing of the stylus at each perforation, and means for releasing the stylus at each perforation and continuing its traversing to another perforation, and means operating with each traversing of the stylus between perforations for transmitting a group of impulses.

SAMUEL W. BALOH. 

